# “whether you think you can, or you think you can’t - you’re right.” - henry ford

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• Whether you think you can, or you think you cant - youre right.- Henry Ford

• Review ofChapter 1: The Atom

• History of Atomic Theories

• Parts of an AtomNucleusProtons: positive charge, mass = 1 amuNeutrons: no charge, mass = 1 amuElectronsNegative charge, mass = 0 amuValence e- are the outermost onesLocated somewhere in orbitals, regions of e- density

amu is an atomic mass unit, a unit of weight

• Remember: # protons = # electrons in uncharged atoms

• Atomic NumberAtomic number is # of protons (and # of electrons)

Mass number is # of protons and neutrons combined, gives weight of atom

• IsotopesIsotopes are different versions of the same elementSame atomic number (# protons)Different mass number (from different # neutrons)

H-1H-2H-3

• Calculating Atomic Mass(amu-1)(%1) + (amu2)(%2) + (amu3)(%3) +

• Electron LocationsElectrons are in orbitalsGround state is the lowest levelElectrons can absorb energy and move to a higher level, or excited stateRelease energy as they drop back down

• Review ofChapter 2: Formulas and Equations

• Formula BasicsSymbols identify elements: K, Na, O, F, Mg, SbFormulas give info from symbols and numbers NaCl NH3 CH3Br

Qualitative info cant be counted (quality). Ex: what elements are presentQuantitative info can be counted (quantity). Ex: how much of each element?

• Writing FormulasCoefficients are written in front of a formula, tells how many of the formula there are 3 CO2 5 H2O 8 NH3Subscripts are small, after symbols, and tell how many atoms there are of each element 3 CO2 5 H2O 8 NH3

• IonsUncharged atoms have same # of protons and electronsIons are atoms that lose or gain electrons, become charged: Cl-, Na+, Cu Polyatomic ions are charged molecules: NH4+, SO4 , NO3-2+2-

• Equalizing Charges

• Naming CompoundsIonic (M/NM) compounds: use name of (+) element (metal), change end of (-) nonmetal to -ide. Ex: NaCl = Sodium chloridePolyatomic ions keep their namesCovalent (NM/NM) compounds: less electronegative atom written first, each is named with mono-, di-, tri-, tetra- prefixes. Ex: N2O4 = Dinitrogen tetroxide

• Roman Numerals in NamesUse a numeral in names when an atom has several options of what its charge can be

Copper (III) sulfate means the copper atom has a +3 charge, as opposed to other possible charges. Cu2(SO4)3Lead (II) nitrate = Pb(NO3)2

• Ch-ch-ch-changesPhysical changes affect form of starting material, but stays same substanceCheese melting, chopping wood

Chemical changes produce new substancesBurning wood, mixing acid & base

• Chemical Reaction EquationsReactant + Reactant Product + Product HCl + NaOH H2O + NaCl

Law of Conservation of Mass says whatevers on the left needs to be on the right, nothing created or destroyed

• 4 Types of ReactionsAddition: A + B CThings come togetherDecomposition: C A + BSomething breaks apartSingle Replacement: AB + C A + BCPart of a compound is replacedDouble Replacement: AB + CD AD + BCAll the pieces of a compound switch around